Much of that which is malignant in the World of Conclave is the result of greed, pride, stupidity or cruelty of humans and other intelligent mortals. There are, of course, spirits, demons and monsters from the Underwater Darkness World that delight in causing pain, suffering and distress amongst the mortal races but powerful masters of wickedness such as demon lords and devil princes are not commonly found masterminding the corruption of mortals. Even Immortals whose actions have caused widespread destruction and mayhem have usually done so from fairly human motives. Lord Three Smoke, arch-enemy of the Celestial Emperor, who provoked the civil war that was the Time of Four Suns, who led an army of creatures of darkness against the Sun God Emperor, slew many Immortals and nearly overturned the Divine Order, did so from a sense of injustice and a genuine claim upon the Celestial Throne. Lady Laughing Corpse is the goddess of disease, but she was once a gentle healing goddess. The power of life and healing was so strong within her that when her body was maimed and broken by the forces of Lord Three Smoke she did not die, but went insane with agony. Even though she now delights in passing that pain to mortals she is attended by her loyal son Master Cinnabar who has passed the Art of healing to mortals in an effort to undo the wrongs of his unfortunate mother.

However, there are always exceptions.

Vuul The Multi-Faceted
There are many legends of a terrible entity with nothing but hatred for creation, composed of pure spite and a lust for destruction. In some legends, the entity is not even redeemed by having these at least vaguely human characteristics. It has no emotional or moral desire to destroy - it just knows no other way.

Most of these legends relate how this entity was halted, dismembered and the parts buried across the world. Legends such as the slaying of the Durag by Mann Son of Bran (where a human hero saved the salsham'ai from a demonic disease that was ravaging their forests), or the formation of the Lake of the Burning Spear (where East Sun pinned an un-named monster beneath the earth with his spear) may echo these legends. Or, as some maintain, they are all the same.

Those in the know name this entity Vuul, also Vuul the Multi-Faceted and Vuul the Shackled One. They say that Vuul is the source of all evil. It may have been temporarily set-back but its essence still leaks into the world and stirs the evil in mortal hearts. They say that Vuul is trapped within the world in many places, and they say that all evil creatures, all evil gods and all evil thoughts and deeds are fragments of Vuul. Lord Three Smoke, the Rebel Dragons, the Queen of Pokan, Red Jade Spirits, all malignant and otherworldly creatures are thought by believers in this philosophy to be fragments of Vuul the Multi-Faceted. Many leaders have found it useful to equate belief systems that they disapprove of (such as the Cult of the Morning Star in Dronistor) with Vuul, even if that link is tenuous at best.

Vuul The Shackled One
Not all who believe in the existance of Vuul follow the idea of a being divided many times. Instead they consider Vuul to be an intact entity, but one that is trapped (the most common theory is beneath the Great Glacier since that is the most Concordant part of the world). Nihilistic cultists seek ways to discover the nature of Vuul's prison and to free the entity but fortunately for the world they are far from succeeding. There are some who theorise that the geomantic layout of Imperial cities stems from some massive form of ritual magic, and that the cities are in fact warding runes that entrap Vuul. If this is the case, it is unknown which cities are important. Furthermore, most cities do not follow exact geomantic rules due to local geography and urban redevelopment over the centuries. Those who hold to the City Ward idea claim that this has weakened the bars of Vuul's prison and increased the evil in the world.

Followers of Vuul
The idea of Vuul is one known only to a few sages and is not disseminated amongst the populace of Conclave. Many cultists could be considered 'Followers of Vuul' by worshipping dark beings that may be a fragment of Vuul The Multi-Faceted, but their goal is more likely to be to gain temporal power and not the release of Vuul and the downfall of creation. The few individuals who do desire this event are normally led by a disgust of the way that society has turned and see an eschatological resolution to be the best way to clear the decks and start again.

It is perhaps fortunate that there is no organised following if Vuul, merely a collection of individuals and small groups who have stumbled upon the secret seperately. The fact that such people tend to be a little paranoid or otherwise deranged makes it less likely that they will team up to form a great world-wide conspiracy. That does not, however, stop others from believing that a worldwide Cult of Vuul exists, or from using that concept to their own ends by scaremongering.

Brotherhood of the Shadowed Moon
Also known as The Dark Sphere, the Brotherhood is a secret organisation dedicated to defeating the Followers of Vuul. They operate independently of any government but may have backing from Imperial Magisters and League Viceroys. Although their goal is the preservation of the world, they see this duty as so important that they are willing to use any and all means necessary to carry it out. If they suspect a village of harbouring Vuul cultists, for example, they may well arrange for the whole village to be destroyed 'just to be sure'.

Using the Followers of Vuul
The concepts of Vuul, Followers of Vuul and the Dark Sphere may be used to add a sinister Cosmic Horror aspect to a campaign. Any existing rules for demon lords, devil princes and other evil or chaotic extraplanar beings can be used for Vuul cultists - who is to say that Orcus, for example, is not just another aspect of Vuul?

The Dark Sphere can be used as patrons for parties of adventurers at first, seeking mercenaries to root out and destroy evil cults (something most good-aligned player characters see as their duty to perform). Over time their more brutal and morally questionable tactics can be revealed, leading the players to wonder how far they are willing to go to destroy evil (one hopes!).

A campaign using Vuul may also benefit from using the sanity rules from the SRD to increase the feel of an unwinnable fight against ancient and overwhelming evil.